WORLD METEOROLOGICAL ORGANIZATION
AND
ECONOMIC AND SOCIAL COMMISSION
FOR ASIA AND THE PACIFIC
WMO/ESCAP PANEL ON TROPICAL CYCLONES
THIRTY-SIXTH SESSION
MUSCAT, OMAN
2 TO 6 MARCH 2009
FOR PARTICIPANTS ONLY
WRD/PTC.36/Doc.4
(12.II.2009)
______________
ENGLISH ONLY
COORDINATION WITH OTHER ACTIVITIES OF THE
WMO TROPICAL CYCLONE PROGRAMME
(Agenda Item 4)
(Submitted by the WMO Secretariat)
SUMMARY AND PURPOSE OF DOCUMENT
This document provides information on activities carried out under
the WMO Tropical Cyclone Programme (TCP) during the inter-sessional period
after the 35th session to assist the Panel in its consideration of coordination
within the TCP (see Annex I). Annex II provides information on the outcome of
the Storm Surge Forecasting Training attachment at the Indian Institute of
Technology (IIT), New Delhi, which was held from 10 to 21 November 2008.
ACTION PROPOSED
The Panel is invited to:
(a)
Review the activities carried out under the TCP since the Thirty-fifth session of
the Panel on Tropical Cyclones (Manama, Bahrain, 5 to 9 May 2008) and the
proposals for the future, which are indicated in Annex I to this document or
otherwise reported to the session;
(b)
Consider what further measures, if any, may be taken to strengthen coordination
between its own activities and those conducted under other parts of the TCP;
(c)
Comment on the summary of the outcome of the "Storm Surge Forecasting
Training attachment at IIT, New Delhi” as given in Annex II.
___________________
ANNEXES:
1.
Activity Report on the Implementation of the WMO Tropical Cyclone Programme
(February 2009)
2.
Summary of the outcome of the “Storm Surge Forecasting Training attachment
at IIT, Delhi " (New Delhi, India, 10 to 21 November 2008)
________________
ANNEX I
Activity Report on the Implementation of the
WMO Tropical Cyclone Programme
(8 February 2009)
1.
Introduction
1.1
The WMO Tropical Cyclone Programme carries out its activities in accordance with
Congress resolutions and Executive Council decisions, implementing activities to achieve the
Expected Results of the WMO Strategic Plan. The resolutions and decisions with particular
relevance to the programme are highlighted in the following sections,
1.2
The WMO Executive Council at its sixtieth session (EC-LX, Geneva, June 2008)
discussed implementation of the Tropical Cyclone Programme and provided guidance under
the Expected Results 1 and 6 of the WMO Strategic Plan.
1.3
With reference to advances in operational weather forecasts and warnings, EC-LX
noted that ensemble prediction techniques have achieved an impressive level of accuracy in
track forecasting. The Council was also noted that there is an increasing need for including
uncertainty information in tropical cyclone forecasts for more effective disaster risk
assessment and management. The Council therefore concluded that greater emphasis
should be given to the use of ensemble techniques and probabilistic forecasting in tropical
cyclone warning operations in order to improve their utility. Making specific reference to the
recommendations of the Sixth International Workshop on Tropical Cyclones (San José,
Costa Rica, November 2006), the Council urged NMHSs and the regional centres concerned
to exploit the use of ensemble techniques in tropical cyclone forecasting and disseminate
probabilistic forecasts in forms and formats suitable for the users. It also requested the
Secretary-General to promote the implementation of operational ensemble prediction
systems and the use of the products and derived information.
1.4
With respect to improving forecast of tropical cyclones and their impacts, the Council
put a high priority on the transfer of research and technique developments between different
tropical cyclone basins, particularly those in forecasting of tropical cyclone tracks and
intensities, rapid intensification, precipitation and storm surges and estimation of related
hazards during tropical cyclone landfall. The Council urged Members operating the TC
RSMCs and TCWCs to transfer research and developments results between the TC regional
bodies with special emphasis on application of intensity forecast guidance for use in TC early
warning systems.
1.5
Recalling the environmental catastrophes during 2007-2008, resulting from tropical
cyclones and their associated coastal marine hazards (mainly storm surges), including the
recent tropical cyclone Nargis that caused such devastation and loss of lives in the most
populous and low-lying areas of Myanmar in May 2008, the Council:
(a)
Noted that some tropical cyclone RSMC advisories did not include storm surge
information;
(b)
Recognized that storm surge warnings are a national responsibility;
(c)
Agreed that a storm surge watch scheme would help to increase advisory leadtime and thus contribute to saving lives and properties, and therefore, requested
the Secretary-General, in consultation with UNESCO/IOC, to develop such
schemes for regions subject to tropical cyclones;
1
ANNEX I
(d)
Urged regional associations concerned to incorporate a storm surge watch
scheme in the tropical cyclone advisory arrangements and in the TCP Regional
Operating Plans and/or Manuals;
(e)
Noting that several RSMCs with Activity Specialization in Tropical Cyclones were
not equipped to function as a storm surge forecast producing centres, requested
the Secretary-General, based on the technical advice of JCOMM, to collect
information on the available capabilities and potential willingness of storm surge
forecast producing centres to participate in regional storm surge watch schemes,
and to develop proposals for consideration by the concerned regional Tropical
Cyclone Programme coordination bodies and regional associations;
(f)
Stressed that such a storm surge watch scheme would be a first step towards a
comprehensive and integrated marine multi-hazard forecasting and warning
system for improved coastal risk management;
1.6
Specifically on Early Warning System (EWS) and services related to coastal risk
management, including observations, telecommunications, detection, forecasting and
warning systems related to tropical cyclones, storm surge, waves and extreme waves, etc,
depend on the crosscutting cooperation of several scientific disciplines and programmes with
specific attention being given to the needs and capabilities of Least Developed Countries
(LDCs) and Small Island Developing States (SIDS). The Council:
(a)
Requested the regional Tropical Cyclone Programme coordination bodies, the
regional associations and the technical commissions concerned, foremost
JCOMM, CHy, CAS and CBS, to set up or strengthen existing collaboration
mechanisms for developing and improving the service delivery in coastal risk
management;
(b)
Invited UNESCO/IOC to participate in the emerging crosscutting coordination
mechanisms;
(c)
Requested the Secretary-General to coordinate this approach with the IOC
Secretariat with a view to advancing coastal risk management activities;
1.8
During the inter-sessional period (March 2008 to February 2009), the following
events were organized or co-sponsored under the Programme:
-
Tropical Cyclone Operational Forecasting Training at RSMC New Delhi –
Tropical Cyclone Centre (New Delhi, India, 9 to 20 February 2009);
-
WMO/ESCAP Panel on Tropical Cyclones, 35th session (Manama, Bahrain, 5
to 9 May 2008);
-
RA IV Workshop on Hurricane Forecasting and Warning, and Public Weather
Services (Miami, USA, 7-19 April 2008);
-
RA IV Hurricane Committee, 30th session (Orland, USA, 23-29 April 2008);
-
RA I Regional Workshop on Tropical Cyclone Research (La Reunion, 26-30
May 2008);
-
RA V Tropical Cyclone Committee, 12th session (Alofi, Niue, 11 – 17 July
2008);
2
ANNEX I
-
Attachment of Typhoon Forecasters from Republic of Korea and Thailand for
Typhoon Operational Forecasting Training at RSMC Tokyo-Typhoon Center
(Tokyo, Japan, 23 July to 1 August 2008);
-
Attachment of Storm Surge Experts from Myanmar and Sri Lanka to the
Indian Institute of Technology (Delhi, India, 10 - 21 November 2008);
-
RA I Tropical Cyclone Committee, 18th session (Lilongwe, Malawi, 6 – 10
October 2008);
-
The 5th TCP/JCOMM Workshop on Storm Surge and Wave Forecasting
(Melbourne, Australia, 1 - 5 December 2008);
-
ESCAP/WMO Typhoon Committee, 41st session (Chiang Mai, Thailand; 19 –
24 January 2009).
In addition, staff of the TCP Division participated in the following activities:
-
RA IV Hurricane Committee, Thirtieth session (Orlando, Florida, USA, 23 – 29
April 2008);
-
RA IV Workshop on Hurricane Forecasting and Warnings, and Public
Weather Forecasting (Miami, Florida, USA, 7 - 19 April 2008);
-
WMO/ESCAP Panel on Tropical Cyclones, Thirty-fifth session (Manama,
Bahrain, 5 – 9 May 2008);
-
WMO Field Mission to Myanmar for Emergency Assessment in the Aftermath
of Tropical Cyclone “Nargis.” Yangon Myanmar, 15 -18 May 2008;
-
RA V Tropical Cyclone Committee, 12th session (Alofi, Niue, 11 – 17 July
2008);
-
RA I Tropical Cyclone Committee, 18th session (Liongwe, Malawi, 6 – 10
October 2008);
-
The 5th TCP/JCOMM Workshop on Storm Surge and Wave Forecasting
(Melbourne, Australia, 1 - 5 December 2008);
-
The Integrated Workshop on "Coping with Climate Change in the Typhoon
Committee Area" in Beijing, China from 22 to 26 September 2008;
-
ESCAP/WMO Typhoon Committee, 41st session (Chiang Mai, Thailand; 19 –
24 January 2009).
1.9
The TCP programme comprises two components: a general component concerned
with collective issues such as methodology and transfer of technology, and a regional
component devoted to the activities of five regional tropical cyclone bodies. The updated list
of Members of these bodies is shown in Appendix I.
2.
General component
2.1
The main activities in the year under review under the general component continued
to be directed towards the publication of manuals and reports, which provide information and
guidance to Members to assist them in the increased application of scientific knowledge and
technology for the improvement of warning and disaster prevention and preparedness
3
ANNEX I
systems corresponding Expected Results I and VI on enhanced capabilities of forecasting
and warning service delivery and disaster risk reduction. Under this component, attention
was also given to the broader aspects of training under the TCP.
2.2
Priorities were given to capacity building to address the issue of sustainable
development with emphases particularly on attachments of forecasters from developing
countries at the different Regional Specialized Meteorological Centres (RSMCs) during the
cyclone season and storm surge/wave experts at the Indian Institute of Technology in
Kharagpur, India, a number of workshops and a joint training event in cooperation with the
Public Weather Service Programme, and a number of Working Group (Committee) sessions
co-joint with Disaster Risk Reduction Programme. These activities are in accordance with
the programme’s objective to facilitate the transfer of knowledge and technology to improve
the institutional efficiency of the NMHSs leading to the provision of better tropical cyclone
track and intensity forecasts and associated flood and storm surge forecasts, and
coordinated actions towards tropical cyclone disaster risk reduction.
2.3
The
TCP
home
page
within
the
WMO
Web
http://www.wmo.int/pages/prog/www/tcp/index_en.html is continuously being updated.
site
2.4
WMO continued to be engaged in the services of Systems Engineering Australlia Pty
Ltd (SEA) to undertake reviews and assessments that would lead to the recommendation of
suitable conversion factors between the WMO 10-minute standard average wind and 1minute, 2-minute and 3-minute “sustained” winds. The SEA has submitted to WMO one
page Executive Summary and technical report which is currently under review by experts.
This undertaking is trying to determine the conversion factors connecting the various wind
averaging periods and its subsequent inclusion into the Global Guide to Tropical Cyclone
Forecasting and the Operational Plans/Manual of the TC regional bodies.
2.5
Tropical
cyclone
news
for
the
WMO
news
website
http://www.wmo.int/pages/mediacentre/news/index_en.html will be continuously provided for
facilitating media outreach.
3.
Regional component
3.1
Many activities of the TCP were carried out under the regional component with a view
to minimizing tropical cyclone disasters through close regional cooperation and coordination.
Major emphasis was placed on improvement in the accuracy of the forecasts, provision of
timely early warnings and on the establishment of necessary disaster preparedness
measures. Each of the tropical cyclone bodies has in place a formally adopted tropical
cyclone operational plan or manual, aimed at ensuring the most effective tropical cyclone
forecasting and warning system with existing facilities, through cooperative agreement on
sharing of responsibilities and on coordinated activities within the respective region. Each of
these bodies was giving attention to the implementation of their technical plan for future
development of services to meet regional needs for upgrading forecasting and warning
facilities and services for tropical cyclones and associated floods and storm surges, as well
as for related disaster risk reduction measures and supporting activities in training and
research.
3.2
The detailed activities under the regional component may be described separately as
below.
4.
ESCAP/WMO Typhoon Committee
4.1
The Forty-first Session of the Committee was held in Chiang Mai, Thailand; 19 – 24
January 2009. It was attended by 102 participants from 12 out of 14 Members of the
Typhoon Committee, namely: Cambodia; China; Hong Kong, China; Japan; Macao, China;
Malaysia; Philippines; Republic of Korea; Singapore; Thailand; the Socialist Republic of Viet
4
ANNEX I
Nam; and the United States of America (USA) and 6 observers from the United Nations
International Strategy for Disaster Reduction Secretariat (UN/ISDR), the Federal Service for
Hydrometeorology and Environmental Monitoring (ROSHHYDROMET) of the Russian
Federation, the United Nations Development Programme (UNDP), the Commission of
Atmospheric Sciences of WMO (CAS/WMO), the Joint Typhoon Warning Center of USA and
the International Civil Aviation Organization (ICAO). Representatives from the Economic
and Social Commission for Asia and the Pacific (ESCAP), the World Meteorological
Organization (WMO) and Typhoon Committee Secretariat (TCS) also attended the session.
4.2
Decisions by the ESCAP/WMO Typhoon Committee at its 41st session can be found
in its final report which will be available in WMO/TCP website.
4.3
The 3rd Typhoon Committee Working Group Meeting for Disaster Prevention and
Preparedness on Typhoon Committee Disaster Information System (TCDIS) and Future
Activities was held in Seoul, Republic of Korea from 10 to 11 April, 2008;
4.4
Publications: The Typhoon Committee Annual Review for the year 2006 was
published in electronic (CD-ROM) format in November, 2007; The TC Newsletter No. 19,
prepared by TCS, was issued in November 2007; The Typhoon Committee Annual Review
for the year 2007 was published in December 2008 (?);
4.5
The Japan Meteorological Agency (JMA) organized the an "Attachment Training" at
the RSMC Tokyo-Typhoon Center from 23 July to 1 August 2008 which was attended by two
female forecasters from Republic of Korea and Thailand;
4.6
The Integrated Workshop on "Coping with Climate Change in the Typhoon
Committee Area" will be held in Beijing, China from 22 to 26 September 2008.
5.
WMO/ESCAP Panel on Tropical Cyclones
5.1
The thirty-fifth session of the WMO/ESCAP Panel on Tropical Cyclones hosted by
WMO was held at WMO Office for West Asia, UN House, Manama, Kingdom of Bahrain
from 5 to 9 May 2008. The session was attended by 18 participants from six (out of eight)
Members of the Panel on Tropical Cyclones, namely, Bangladesh, India, Maldives, Pakistan,
Sri Lanka and Thailand. It was also attended by observers from China, Indian Institute of
Technology (IIT) Delhi, Bahrain Meteorological Service, United Nations Development
Programme (UNDP) and representatives from WMO, UNESCAP and Technical Support Unit
(TSU).
5.2
Decisions by the WMO/ESCAP Panel on Tropical Cyclones at its 35th session can
be found in its final report which is available in WMO/TCP website.
5.3
Attachment of two forecasters from Bangladesh and Maldives was arranged by WMO
and the RSMC New Delhi from 9 to 20 February 2009 for the on-the-job training at the
RSMC on operational analysis and forecasting of tropical cyclone.
5.4
Two storm surge experts from Myanmar and Sri Lanka underwent training (10 to
21 November 2008) at the Indian Institute of Technology (Delhi) in the implementation and
running of a PC-based high-resolution storm surge model.
5.5
Publications: a) Panel News No.24 was published in October 2007 by TSU and had
already been distributed to the Members and others concerned. The 25th issue of the Panel
News which was published in April 2008, was distributed to the Members during the 35th
Session of PTC; b) The Panel on Tropical Cyclones Annual Review for the year 2006 which
was consolidated and finalized by the Chief Editor, Dr. H.R. Hatwar (India) with contributions
5
ANNEX I
from the National Editors was submitted to WMO in January 2008 for publication as soon as
possible.
6.
RA I Tropical Cyclone Committee (RA I/TCC) for the South-West Indian Ocean
6.1
The RA I Regional Workshop on Tropical Cyclone Research was held from 26 to 30
May 2008, in St. Dennis, La Reunion, France. WMO sponsored 10 participants from the
Committee to attend the workshop. The workshop was focused on: 1) gathering the cyclone
research community in the south-west Indian Ocean basin, sharing the ongoing research
and triggering collaboration topics; 2) identifying what the operational cyclone forecasting
community can expect from numerical research models, satellite observations and
measurement campaigns in the next few years over the south-west Indian ocean, and topics
in need of further progress in research to satisfy operational cyclone forecasting
requirements.
6.2
The 18th RA I Tropical Cyclone Committee Session took place in Lilongwe, Malawi, 6
– 10 October 2008 in conjunction with WMO/DRR meeting for a pilot demonstration projects
in Early Warning Systems with a multi-hazard approach in the region. The session was
attended by the representatives from 15 member countries and Australia as an ex-officio
Member of the Committee. Also in attendance were RA I Working Group on Hydrology,
International Civil Aviation Organization (ICAO), UNOCHA and representatives of the WMO
Secretariat.
6.3
The Committee agreed to set up an ad-hoc group to address the issue related to
storm surge in the region, which will be composed of Chairperson of the Committee and the
experts nominated by Mauritius, RSMC La Reunion, South Africa, Mozambique,
Madagascar, Seychelles and Kenya. The experts will be from the fields of meteorology,
marine meteorology and disaster management. The ad-hoc group will, inter-alia, consider
the; the vulnerability of Members, the specific communities under risk, monitoring facilities
and gaps, model outputs and response measures.
7.
RA IV Hurricane Committee
7.1
The Government of the USA hosted an RA IV Workshop on Hurricane Forecasting
and Warning, and Public Weather Services in Miami, 7 - 19 April 2008. It was organized by
the NWS/NOAA Tropical Prediction Center/National Hurricane Center in cooperation with
WMO (TCP Division and PWS Division). The workshop was conducted with simultaneous
interpretation between English and Spanish, and attended by 21 participants from eighteen
Members of RA IV. And the next is in preparation, and plan to be held in Miami, USA, from
23 March to 3 April 2009.
7.2
The thirtieth session of the Hurricane Committee was held in Orlando, Florida, USA,
from 23 – 28 April 2008, co-joint with WMO Disaster Risk Reduction Programme. The
session was attended by 52 participants, including 41 RA IV Member states of the
Committee, observers from Spain, Caribbean Disaster Emergency Response Agency
(CDERA), Caribbean Institute for Meteorology and Hydrology (CIMH), World Bank, and
International Strategy for Disaster Reduction (ISDR).
7.3
Decisions by the RA IV Hurricane Committee at its 30th session can be found in its
final report which is available in WMO/TCP website.
7.4
Second Course on the Use and Interpretation of Products, Santa Cruz de la Sierra,
26-30 November 2007;
6
ANNEX I
8.
RA V Tropical Cyclone Committee (RA V/TCC) for the South Pacific and
South-East Indian Ocean
8.1
The twelfth session of the RA V Tropical Cyclone Committee was held in Alofi, Niue,
11 – 17 July 2008. The session was the first that discussed implementation of the decision
by the Executive Council at its 60th session on possible institutional arrangements of storm
surge forecasting and warning advisories (Storm Surge Watch Scheme) to be included in
the RSMC/TCWC Tropical Cyclone Advisories. Furthermore, a Severe Weather Forecast
Demonstration Project in RA V (RA V-SWFDP) was introduced during the session;
8.2
Decisions by the RA V Tropical Cyclone Committee at its 12th session can be found
in its final report which is available in WMO/TCP website;
8.3
Training on Operational Tropical Cyclone Forecasting at RSMC, Nadi, Fiji, from 3 to
13 December 2007. Two participants from two countries participated in the on- the-job
training programme on tropical cyclone forecasting methods and techniques, as well as
familiarization with RSMC Nadi operations;
8.4
The 2006, 2007 and 2008 Pacific International Desk Training Programme, Honolulu,
Hawaii Islands, USA. About fifteen participants from about eleven countries participated in
this programme during the 2006-2008 period.
8.5
Many other training events organized by Members, regional organizations and
institutions, which can be found in the Attachment II of Appendix V of the final report of the
12th Session of the RA V Tropical Cyclone Committee, available at WMO/TCP website.
9.
Cooperation with other organizations
9.1
In accordance with the wishes of the WMO Congress, and Executive Council, close
cooperation with other international and regional organizations has strengthened. Thus,
there has been close cooperation and collaboration with the Economic and Social
Commission for Asia and the Pacific (ESCAP), the International Strategy for Disaster
Reduction (ISDR) Secretariat, the Asian Disaster Reduction Center (ADRC), the
International Federation of Red Cross and Red Crescent Societies (IFRC), the Joint
WMO/IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM),
SOPAC and SPREP and other organizations, on a variety of matters of common concern.
The main items include ESCAP's co-sponsorship of the Typhoon Committee and the Panel
on Tropical Cyclones, as well as the ISDR Secretariat and the ADRC’s involvement in the
disaster risk reduction component of the TCP, in particular in the context of the ISDR.
9.2
As part of the long-established close working relationship between WMO and the
International Civil Aviation Organization (ICAO), a number of the TC RSMCs and Tropical
Cyclone Warning Centres have also been designated as ICAO Tropical Cyclone Advisory
Centres (TCAC) by ICAO Regional Air Navigation Agreements. The centres, listed below,
provide specialized tropical cyclone warning services for the aviation community:
RSMC/TCWC
Area of responsibility
Darwin (Australia)
Ocean
South-eastern Indian Ocean, South-western Pacific
Honolulu (USA)
Central North Pacific
La Réunion (France)
South-western Indian Ocean
Miami (USA)
North Atlantic, Caribbean, Eastern North Pacific
7
ANNEX I
Nadi (Fiji)
Southern Pacific
New Delhi (India)
Bay of Bengal and the Arabian Sea,
i.e. N: Coastal line; S: 5N/10N; E:100E; W: 45E
Tokyo (Japan)
Western North Pacific, including the South China Sea
9.3
On a regional basis, WMO, through its Tropical Cyclone Programme, has fostered
and maintained close collaboration and fruitful coordination with regional bodies concerned
with disaster risk reduction issues, in particular with the Asian Disaster Preparedness Center
(ADPC), the Asian Disaster Reduction Center (ADRC), the Caribbean Disaster Emergency
Response Agency (CDERA), and the South Pacific Regional Environment Programme
(SPREP), and UN-ISDR Africa and Central America.
10.
Programme for 2009
10.1 The TCP covers a wide range of activities which are of a continuing and long-term
nature. Preceding sections of this report contain an overview of several of the ongoing
activities and, in some instances, indications have been given of the plans for the period
ahead. The main parts of the 2009 programme are set out below in summary form:
General component
(a)
Follow-up activities on the WMO Strategic Plan;
(b)
Updating of the TCP home page within the WMO Web site, and developing the
Tropical Cyclone Forecaster web site (TCP Sub-project No. 24) which will serve as a
source for tropical cyclone forecasters to obtain forecasting and analytical tools and
techniques for tropical cyclone development, motion, intensification, and wind
distribution, and so on; Arrangements on establishment of the Tropical Cyclone
Forecasting Website, which is designated to dedicate tropical cyclone forecasting
techniques, methodologies and other related knowledge, is underway, and hopefully
to be launched sometime in 2009;
(c)
Attachment of forecasters to all six TC RSMCs during the cyclone season;
(d)
Continue to implement the following TCP sub-projects, endorsed by Congress XV
(Geneva, 2007):

Sub-project No. 23 - "Combined Effects of Storm Surges and River Floods in
Low Lying Areas" (also endorsed Executive Council LX (Geneva, 2008);

Sub-project No. 25 - "Study on the economic and societal impacts of tropical
cyclones" (also endorsed Executive Council LX (Geneva, 2008);

Sub-project No. 26: “Evaluation of tropical cyclone warning systems (their
effectiveness and deficiencies)”.
Arrangements on implementing the above subprojects have been made.
(e)
Support and coordination to update the Global Guide on Tropical Cyclone
Forecasting in response to recommendation from the IWTCs. The Guide is due to be
completed around the end of 2009;
(f)
Coordination of the services and activities of six TC RSMCs (Miami, Tokyo, Honolulu,
New Delhi, La Reunion and Nadi) and TCWCs (Darwin, Perth, Brisbane, Wellington,
8
ANNEX I
Port Moresby and Jakarta) with a view to improving regional services of the centers.
Review of the global standards in forecasting techniques and warning services
including those for data exchange and forecasts verification.
(g)
Outreach to media and general public by posting tropical cyclone information to the
WMO news website, and responding by email to inquiries related to tropical cyclones
around the globe.
Regional component
10.2 Under the regional component, the programme will be mainly concerned with the
activities undertaken by the five regional tropical cyclone bodies and the implementation of
the decisions they make. A provisional schedule for the period July 2008 to June 2009 of
meetings and training events within or related to the TCP, is given below:
-
Typhoon Committee Workshop on Ensemble Forecasting
of Korea; May 2009);
-
ESCAP/WMO Typhoon Committee, 41stth session (Chiang Mai, Thailand; 19
- 24 January 2009);
-
WMO/ESCAP Panel on Tropical Cyclones, 36th session (Muscat, Oman; 2-6
March 2009);
-
WMO/ESCAP Panel on Tropical Cyclones High-Level Policy Working Group
Meeting (Muscat, Oman, 27 – 28 February 2009);
-
The First International Conference on Indian Ocean Tropical Cyclones and
Climate Change (Muscat, Oman; 8 – 11 March 2009);
-
RA IV Workshop on Hurricane Forecasting and Warning, and Public Weather
Services (Miami, USA, 23 March to 3 April 2009);
-
RA IV Hurricane Committee, 31th session (Bahamas; 20 - 24 April 2009).
-
Experts Meeting on Tropical Cyclone Warnings (in 2009; place and dates to
be determined);
-
TC RSMC Technical Coordinating Meeting (in November 2009; place and
dates to be determined);
-
Regional Conference on Tropical Cyclones (in 2009; place and dates to be
determined);
-
Regional Workshop on Probabilistic Tropical Cyclone Forecasting (in 2009;
place and dates to be determined);
-
South Hemisphere Training Courses on Tropical Cyclone Forecasting and
Warnings (29 September to 17 October 2009);
-
ESCAP/WMO Typhoon Committee Roving Seminar (Nanjing, China;
September 2009);
-
The Second International Workshop on Tropical Cyclone Landfall Processes
(Shanghai, China; October 2009)
9
(Jeju, Republic
ANNEX I
-
Forecaster Attachment Trainings in RSMC New Delhi, RSMC Nadi, RSMC
Tokyo and Indian Institute of Technology Delhi (Dates to be determined).
Important inter-sessional activities will include:
-
As appropriate, preparation, editing, updating, publication and distribution of new
editions or supplements to the Tropical Cyclone Operational Plans for the Bay of
Bengal and Arabian Sea (English only), the South-West Indian Ocean (English
and French), the South Pacific and the South-East Indian Ocean (English and
French), the Hurricane Committee Region (English and Spanish) and the
Operational Manual for the Typhoon Committee Area (English only);
-
Distribution of updated technical plans for further development of the Regional
Cooperation Programmes of the five regional tropical cyclone bodies;
-
Preparation and publication of the Typhoon Committee Annual Review for 2007
and Newsletter of 2008;
-
Preparation and publication of Panel on Tropical Cyclones Annual Review for
2008 and Panel News.
and, in more general terms:
-
Activities for the implementation of of the Tropical Cyclone Programme section of
the WMO Strategic Plan;
-
Implementation of activities within the framework of the International Strategy for
Disaster Reduction (ISDR);
-
Follow-up activities aimed at implementation of decision of the UN World
Conference of Small Island Developing States (SIDS) (Mauritius, January 2005)
and the World Conference on Disaster Reduction (Kobe, Japan, January 2005);
-
Continued activities for the implementation of the Regional Cooperation
Programmes, Technical Plans and other work programmes of the regional
tropical cyclone bodies;
-
Work of study groups, sub-groups and rapporteurs established by the regional
tropical cyclone bodies, e.g. training and research activities in the meteorological
component of the Typhoon Committee's programme under the leadership of the
Coordinator, typhoon Training and Research Coordinating Group (TRCG), and
the rapporteur on updating of the Typhoon Committee Operational Manual, the
Working Group on the Panel on Tropical Cyclones Coordinated Technical Plan,
the implementation of satellite based telecommunications regional networks, and
on regional activities on storm surges
-
action on further proposals made by the Fifteenth WMO Congress, the Executive
Council, the Regional Associations concerned and the regional tropical cyclone
bodies.
______________________
10
Appendix 1
TCP REGIONAL BODIES
ESCAP/WMO TYPHOON
COMMITTEE
WMO/ESCAP PANEL
ON TROPICAL CYCLONES
RA I TROPICAL CYCLONE
COMMITTEE FOR THE
S.W. INDIAN OCEAN
RA IV HURRICANE COMMITTEE
RA V TROPICAL CYCLONE
COMMITTEE FOR THE S. PACIFIC
AND S.E. INDIAN OCEAN
(14 Members)
(8 Members)
(15 Members)
(26 Members)
(17 Members)
CAMBODIA
CHINA
DEM. PEOPLE'S REP. OF KOREA
HONG KONG, CHINA*
JAPAN@
LAO PDR
MACAO, CHINA*
MALAYSIA
PHILIPPINES
REPUBLIC OF KOREA
SINGAPORE
THAILAND
USA
VIET NAM, SOCIALIST REPUBLIC OF
BANGLADESH
INDIA@
MALDIVES
MYANMAR
OMAN
PAKISTAN
SRI LANKA
THAILAND
BOTSWANA
COMOROS
FRANCE@
KENYA
LESOTHO
MADAGASCAR
MALAWI
MAURITIUS
MOZAMBIQUE
NAMIBIA
REP. OF SOUTH AFRICA
SEYCHELLES
SWAZILAND
UNITED REPUBLIC OF TANZANIA
ZIMBABWE
ANTIGUA & BARBUDA
BAHAMAS
BARBADOS
BELIZE
BRITISH CARIBBEAN TERRITORIES*
CANADA
COLOMBIA
COSTA RICA
CUBA
DOMINICA
DOMINICAN REPUBLIC
EL SALVADOR
FRANCE
GUATEMALA
HAITI
HONDURAS
JAMAICA
MEXICO
NETH. ANTILLES AND ARUBA*
NICARAGUA
PANAMA
ST. LUCIA
TRINIDAD AND TOBAGO
UK
USA@
VENEZUELA
AUSTRALIA
COOK ISLANDS
FIJI@
FRENCH POLYNESIA*
INDONESIA
KIRIBATI
MICRONESIA
NEW CALEDONIA*
NEW ZEALAND
NIUE
PAPUA NEW GUINEA
SAMOA
SOLOMON ISLANDS
TONGA
UNITED KINGDOM
USA#
VANUATU
@RSMC
Tokyo - Typhoon Center
@ RSMC-Tropical
@
Cyclones-New Delhi
@ RSMC
* Member Territories
La Réunion - Tropical Cyclone
Centre
RSMC Miami - Hurricane Center
Non-Members of WMO (6):
- EAST TIMOR
- MARSHALL ISLANDS
- NAURU
- PALAU
- TOKELAU
- TUVALU
@ RSMC
#
Nadi - Tropical Cyclone Centre
RSMC Honolulu - Hurricane Center
ANNEX II (1)
WMO/TCP Training Programme
Organized at
Indian Institute of Technology (IIT),
New Delhi, INDIA
(10 November – 21 November, 2008)
On
Design of Experiments for Understanding Storm Surge Phenomena & Testing
the IIT Model
(Case studies with Synthetic data and real track of 2008 Nargis Cyclone)
Reported by
May Khin Chaw
Department of Meteorology & Hydrology
Yangon, MYANMAR
ANNEX II (1)
Design of Storm Surge Experiments – Understanding storm surge
phenomena under various environmental forcing conditions
Experiment 0:
This section provides information on how to implement the Storm Surge model in
Linux Operating System. It also contains “README” file which lists the Source programs
(FORTRAN code), the “Input Files” needed to run the storm surge model, and a list of
“Output Files” generated during the model computation.
Visualization of the model computed parameters are made using the post-processing
software called “GMT” (Generic Mapping Tools). The output from GMT is a “Postscript” file
which can be further converted to any Image format using “Ghostscript” (default in Linux
operating system).
Effect of Basin scale Bathymetry:
The objective of this experiment was to understand the sensitivity of ocean bottom to
storms on water surface, and the resulting storm-surge as it approaches near-shore waters.
In this context, four experiments are planned using different combination of bathymetry (viz;
10m, 50m, 100m, imposing a condition of uniform depth (5m) if water depth is less than or
equal to 40m). The conclusions obtained from these various experiments are listed in the
section called “conclusions”. The various parameters set during the experimental phase are
as follows:
Experiment 1: Uniform depth of entire basin (10 m)
Ten points (Track )
Starting point –
15.8˚ N, 90.1˚ E
Ending point _
18.3˚ N ,97.5˚ E
KS
_
3240
K1
_
3240
ND
_
10
DelT
_
60 Sec
Simulation of model run
54 hrs
Maximum value of peak surge = (7.138765 m)
Experiment 2: Uniform depth of entire basin: (50 m)
Ten points (Track)
Starting point
15.8˚N, 90.1˚E
Ending point
18.3˚N, 97.5˚E
Simulation of model run - 54 hrs
Maximum value of peak surge =
(1.751925 m)
Experiment 3: Uniform depth of entire basin (100 m)
Ten points (Track)
Starting point
15.8˚N, 90.1˚E
Ending point
18.3˚N, 97.5˚E
Simulation of model run - 54 hrs
Maximum value of peak surge = (0.8965402 m)
Experiment 4: Uniform depth of 5m if depth is less than or equal to 40m.
Ten points (Track)
1
ANNEX II (1)
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run - 54 hrs
Maximum value of peak surge = (7.387425m)
Conclusions:
Experiment 1-4: was carried out using ten points along the cyclone track. The
parameters in the “track.dat” are similar for all the four experiments, except the bathymetry.
It could be investigated that storm-surge is very sensitive to basin depths. The results show
that the entire basin with uniform depth of 10m lead to the maximum surge height. That
means the shallowness of the water in coastal areas may considerably magnify the surge
heights in the region. The surge height was found to decrease when the water depths
increased.
Effect of Landfall Angle:
The objective of this experiment to study the associated storm-surge for three
different directions on its way to land-fall. The experiment has been designed to investigate
the storm-surge for three tracks viz; (1) perpendicular track (ii) northerly and (iii) southerly
track, assuming the cyclone is making its landfall to Deltaic area near Pathein. Each of these
simulations are performed with real depth data. The details of this simulation experiment is
as follows:
Experiment 5:
Cyclone land falling perpendicular to the coast
Three points (Perpendicular Track)
Starting point
16.0˚N, 91.1˚E
Ending point
16.8˚N,96.0˚E
Simulation of model run - 30 hrs
Maximum value of peak surge = (3.42370m)
Experiment 6:
Cyclone landfalling northerly to the coast
Three points (Northerly Track)
Starting point 14.5˚N, 91.1˚E
Ending point 16.8˚N, 96.0˚E
Simulation of model run - 30 hrs
Maximum value of peak surge = (3.416774m)
Experiment 7:
Cyclone landfalling southerly to the coast
Three points (Southerly Track)
Starting point 13.5˚N, 91.1˚E
Ending point 16.8˚N, 96.0˚E
Simulation of model run - 30 hrs
Maximum value of peak surge = (3.394487m)
Conclusions:
The location of highest surge depends predominantly on the angle of landfall. It has
been the experience that the cyclones of similar intensity generate surges having different
amplitudes depending upon the angle of landfall at a particular location. From Experiments
2
ANNEX II (1)
5-7, cyclones making landfall to the coast at uniform water depths is considered along a
straight track. It has been noticed that the perpendicular track generated the highest surge
compared to the northerly and the southerly track. The anomalies in the relative magnitudes
of associated surges using the three tracks are comparable.
Effect of wind stress forcing:
The objective of this experiment is to study the role of wind stress in the overall
computation of storm-surges. The experiment is designed to study the anomalies in storm
surges employing varied formulation of storm surge models (i) using Delta-P formulation
and (ii) R-max .
Experiment 8: with DP (65hPa)
Cyclone making landfall at Deltaic near Pathein.
Water depth _
Real water depth (depth.dat)
DelP
_
65 hPa
Starting point –
15.8˚N, 90.1˚E
Ending point _
18.3˚N, 97.5˚E
Simulation of model run _ 54 hrs
Maximum value of peak surge = (6.447352m)
Experiment 9: with DP 60 hPa (- 5 hPa)
Cyclone making landfall at Deltaic near Pathein.
Water depth _
Real water depth (depth.dat)
DelP 60 hPa
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run - 54 hrs
Maximum value of peak surge =
(5.962650m)
Experiment 10: with DP 70 hPa (+ 5 hPa)
Cyclone making landfall at Deltaic near Pathein.
Water depth Real water depth (depth.dat)
DelP 70 hPa
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run - 54 hrs
Maximum value of peak surge = (6.941465 m)
Conclusions:
Experiments 8-10 are carried out to examine the sensitivity of the cyclone parameter,
the pressure drop, on the storm surge development. It has been noticed that larger
differences in Delta-P (pressure drop) leads to higher surges.
Experiment 11: with DP (65hPa)
Cyclone making landfall at Deltaic near Pathein.
Water depth Real water depth (depth.dat)
DelP 65 hPa
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run 54 hrs
3
ANNEX II (1)
Maximum value of peak surge = (6.447352m)
Experiment 12: with DP 55 hPa (-10 hPa)
Cyclone making landfall at Deltaic near Pathein.
Water depth Real water depth (depth.dat)
DelP 55 hPa
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run 54 hrs
Maximum value of peak surge = (5.645126m)
Experiment 13: with DP 75 hPa (+ 10 hPa)
Cyclone making landfall at Deltaic near Pathein..
Water depth Real water depth (depth.dat)
DelP 75 hPa
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run 54 hrs
Maximum value of peak surge = (7.359879 m)
Conclusions:
Again using real bathymetry and large differences in the pressure drop (Delta-P), it
was noticed higher surges are associated with larger differences in the pressure drop.
Experiment 14: with Rmax 25kms
Cyclone making landfall at Deltaic near Pathein..
Water depth Real water depth (depth.dat)
DelP 65 hPa
Rmax 25 kms
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run 54 hrs
Maximum value of peak surge = (6.447352 m)
Experiment 15: with Rmax 15kms (- 10 kms)
Cyclone making landfall at Deltaic near Pathein..
Water depth Real water depth (depth.dat)
DelP 65 hPa
Rmax 15 kms
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run 54 hrs
Maximum value of peak surge = (4.548517 m)
Experiment 16: with Rmax 35kms (+ 10 kms)
Cyclone making landfall at Deltaic near Pathein.
Water depth Real water depth (depth.dat)
DelP 65 hPa
Rmax 35 km
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Simulation of model run 54 hrs
4
ANNEX II (1)
Maximum value of peak surge = (8.294783 m)
Conclusions:
Experiments 14-16 are conducted with different values of Radius of Maximum winds
(R-max). Three different values for R-max were selected which being 15, 25 and 35 Kms.
The overall computation choosing these three different values show that Larger differences
in Rmax (Radius of Maximum winds) leads to higher surges.
Effect of storm-surge on duration of energetic event:
(Response of storm-surge to fast moving cyclones)
Evolution and amplitude of Surge depends critically upon the duration of the cyclone
over the continental shelf, especially for closed regions like Bay of Bengal. In order to find
out this, the following two experiments are carried out.
Experiment 17: Cyclone duration 54 hrs (slow moving)
Cyclone making landfall at Deltaic near Pathein.
Water depth Real water depth (depth.dat)
KS, K1 3240
Cyclone duration 54 hrs
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Maximum value of peak surge = (4.523909 m)
Experiment 18: Cyclone duration 27 hrs (fast moving)
Cyclone making landfall at Deltaic near Pathein.
Water depth Real water depth (depth.dat)
KS,K1 3240
Cyclone duration 27hrs
Starting point 15.8˚N, 90.1˚E
Ending point 18.3˚N, 97.5˚E
Maximum value of peak surge = (7.212059 m)
Conclusions:
Experiment 17 and 18, are conducted with cyclone moving along a straight track making its
landfall at Deltaic area near Pathein. The experiment was aimed to study the response of
forward motion of cyclone on the associated storm-surge. Likewise, for the straight track
cyclone making landfall at two different time intervals viz; 54 hrs and 27 hrs. The
experiments signify that fast moving cyclone results in maximum surge compared to a slow
moving cyclone.
5
ANNEX II (1)
Figure -1: Uniform depth Entire Basin (10m)
(Maximum value of peak surge = (7.138765 m))
Figure -2: Uniform depth Entire Basin (50m)
(Maximum value of peak surge = (1.751925 m))
6
ANNEX II (1)
Figure -3: Uniform depth Entire Basin (100m)
(Maximum value of peak surge = (0.8965402 m))
Figure -4: Uniform depth of 5m if water depth is less than or equal to 40 m
(Maximum value of peak surge = (7.387425 m))
7
ANNEX II (1)
Figure -5: Cyclone land-falling perpendicular to coast
(Maximum value of peak surge = (3.42370 m))
Figure -6: Cyclone track land-falling northerly to coast
(Maximum value of peak surge = (3.416774 m))
8
ANNEX II (1)
Figure -7: Cyclone track land-falling southerly to coast
(Maximum value of peak surge = (3.394487 m))
Figure -8: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P = 65 mb, Rmax = 25 kms)
(Maximum value of peak surge = (3.394487 m))
9
ANNEX II (1)
Figure -9: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P = 60 mb, Rmax = 25 kms)
(Maximum value of peak surge = (5.962650 m))
Figure -10: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P = 70 mb, Rmax = 25 kms)
(Maximum value of peak surge = (6.941465 m))
10
ANNEX II (1)
Figure -11: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P =65 mb, Rmax = 25 kms)
(Maximum value of peak surge = (6.447352 m))
Figure -12: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P = 55 mb, Rmax = 25 kms)
(Maximum value of peak surge = (5.645126 m))
11
ANNEX II (1)
Figure -13: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P = 75 mb, Rmax = 25 kms)
(Maximum value of peak surge = (7.359879 m))
Figure -14: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P = 65 mb, Rmax = 25 kms)
(Maximum value of peak surge = (6.447352 m))
12
ANNEX II (1)
Figure -15: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P = 65 mb, Rmax = 15 kms)
(Maximum value of peak surge = (4.548517 m))
Figure -16: Cyclone making landfall to the deltaic near Pathein
(Using real water depth, Delta-P = 65 mb, Rmax = 35 kms)
(Maximum value of peak surge = (8.294783 m))
13
ANNEX II (1)
Figure -17: Impact of Duration of Cyclone over the Sea
(Using real data, Duration = 54 hrs)
(Maximum value of peak surge = (4.523909 m))
Figure -18: Impact of Duration of Cyclone over the Sea
(Using real data, Duration = 27 hrs)
(Maximum value of peak surge = (7.212050 m))
14
ANNEX II (1)
Validation of IIT Storm Surge Model
In order to validate the models, several simulation experiments have been performed
by using the data of severe cyclonic storms hitting the coasts of Myanmar. In the present report
an attempt has been made to compare the simulated sea surface elevations with post storm
survey estimates of Meteorological Departments of Myanmar. The model computed surges for
1982 Gwa, 2006 Mala and 2008 Nargis cyclones are in good agreement with the available
observational estimates.
(1) Gwa Cyclone (May 1982)
The model is integrated with a pressure drop of 55 hPa and radius of maximum winds
of 30 km. The model computed surge contours along the Myanmar coast are shown in Figure
1. A maximum surge of 4.14 m is predicted to the right of the landfall point near Gwa. During
this cyclone the surge of 3.7 m was reported along the Southern coast of Rakhine near Gwa
(Dept. of Meteorology & Hydrology, Myanmar). This is in good agreement with our simulated
sea level elevations.
Figure 1: Surge contours (m) associated with 1982 Gwa cyclone
(2) Mala Cyclone (April 2006)
The model is integrated with a pressure drop of 48 hPa and radius of maximum
winds of 40 km. The model computed surge contours along the Myanmar coast are shown in
Figure 2. A maximum surge of 4.51 m is predicted by the model. Peak storm surge of about
4.57 m was reported for the May 2006 Mala cyclone on the Rakhine coast near Gwa by the
Department of Meteorology and Hydrology, Yangon.
15
ANNEX II (1)
Figure2: Surge contours (m) associated with 2006 Malar cyclone
(3) Nargis Cyclone (May,2008)
The model (9.1 x 9.1 KM resolution) is integrated with a pressure drop of 65 hPa and
radius of maximum winds of 25 km for Nargis cyclone, May 2008. The model computed surge
contours along the coast of Myanmar are shown in Figure 3. It may be seen that a maximum
surge of 4.5 m is occurred close to the landfall point. However, Peak storm surge of about 7
m was reported for the Nargis cyclone on the Deltaic area by the Department of Meteorology
and Hydrology, Yangon. The difference between model output and observed data may be
because of coastal geometry. Irrawaddy River flows south and splitting into numerous
distributaries known as the Mouths of the Irrawaddy. The accelerated surges came up the
numerous distributaries at the mouths of Ayeyarwady river up to (15-40) miles inland &
combine with the stream flow. After that coastal plains are flooded.
Figure3: Surge contours (m) associated with 2008 Nargis cyclone
16
ANNEX II (1)
After running the model with high resolution model, the result shows (Figure 4)
maximum surge height of 6.3m. The computed surge height is in good agreement with the
observed surge height.
Figure 4: Surge contours (m) associated with 2008 Nargis cyclone with fine resolution
model (max value 6.3 m)
General conclusions
In this report, 2008, Nargis cyclone data is used to run the IIT storm surge model. 18
experiments were carried out to test the model sensitivity to various input parameters
(bathymetry, landfall angle, pressure drop, and the radii of maximum wind and the duration
of the cyclone over the sea). In order to validate the models, several simulation experiments
have been performed by using the data of severe cyclonic storms hitting the coasts of
Myanmar : Gwa (1982) and Mala (2006). Results of the experiments and their significance
were examined in detail.
After several experiments have been performed, model outputs show that IIT model
is in good agreement with reported observation. The IIT model will provide useful guidance
for the forecasters and it will be very useful to improve their storm surge forecasting abilities.
After successful implementation of the model in Department of Meteorology and
Hydrology, Myanmar, if there is tropical cyclone in Bay of Bengal, it would be possible to run
the model and give an accurate storm surge forecast for Myanmar. Moreover, several
experiments on historical data can be performed with this model. It will benefit somehow on
coastal protective works.
The knowledge and the experience gained from this training will be shared with the
colleagues of Department of Meteorology and Hydrology when I go back.
Acknowledgement:



I would like to record my heartfelt gratitude to Prof. S. K. Dube, Prof A. D. Rao,
and Dr Indu Jain for their guidance and sharing experiences during my stay at IIT
Delhi.
Sincere thanks to TCP Training Programme of World Meteorological
Organization (WMO), without their financial support my training in the India would
not have been realized.
I would also like to acknowledge to all the staff of Ocean State Forecasting
Division, Center for Atmospheric Sciences, IIT Delhi for their friendly responds
and
efforts
to
provide
all
necessary
help.
17
ANNEX II (2)
WMO/TCP Training Programme
Organized at
Indian Institute of Technology (IIT),
New Delhi, INDIA
(10 November – 21 November, 2008)
on
Storm Surge Modelling & Forecasting for Sri Lanka
(Case studies with Synthetic data and Real track of 1978 Batticaloa, Cyclone)
Reported by
Ajith L. K. Wijemannage
Department of Meteorology
Colombo 07
Sri Lanka
Report of IIT Storm Surge Modeling & Forecasting for Sri Lanka
Experiments For Understanding
Storm Surge Phenomena and Testing the IIT Model
1.
Introduction
Most of the tropical cyclones forming in the Bay of Bengal hit the coast of India and West
Bengal every year, causing heavy loss of life and property. The shallow waters of the Bay of
Bengal, the low flat coastal terrain, and funneling shape of the coastline can lead to devastating
losses of life and property due to the surge from a storm of even moderate intensity.
The impacts of the landfall cyclones are the highest on a given landmass. However, land
masses nearby an active cyclone also get affected due to winds and the feeder bands of the
cyclone. Sri Lanka, an island in the North Indian Ocean, gets affected by cyclones if they landfall
or when a passing nearby cyclone have wide feeder bands. That is why whenever tropical
cyclones develop in the Bay of Bengal below latitude 10°N, cyclone alert bulletins and warnings
are issued by the Sri Lanka Meteorological Department.
During the past 126 year period (1881- 2007), only eleven cyclonic storms and five
cyclones crossed the coasts of Sri Lanka. Moreover, four out of five cyclones had landfall on the
east coast during the months of November and December. Nine out of eleven cyclonic storms
have also made landfall during the months of November and December. The other three (one
cyclone and two cyclonic storms) were in the months of January, March and October.
2.
Objectives
 To understand the basic features of the storm surge phenomena through numerical
simulations for Sri Lanka region.
 Perform numerical experiments to test the feasibility and sensitivity of the storm surge
model.
3.
Experimental Set Up and Rationale
Coastal regions of many countries are threatened by the possibility of storm surge floods
whenever a tropical cyclone approaches. Storm surge disasters cause heavy loss of life and
property, damage to the coastal structures and the losses of agriculture which lead to annual
economic losses in these countries. Thus the real time monitoring and warning of storm surge is of
great concern for this region.
In order to achieve greater confidence in surge prediction one should have the good
knowledge of the input parameters for the model. These parameters include the oceanographic
parameters, meteorological parameters (including storm characteristics), hydrological input, basin
characteristics and coastal geometry, wind stress and sea bed friction and information about the
astronomical tides. It has been seen that in many cases these input parameters strongly influence
the surge development.
In order to provide full insight of the storm surge phenomenon and full appreciation of the
problem, following experiments were designed for the participant.

3.1
Experiment 0: Learn how to run the model in windows/Linux environment. Visualization
of the model computed parameters are made using the post-processing software called
“GMT” (Generic Mapping Tools). The output from GMT is a “Postscript” file which can be
further converted to any Image format using “Ghostscript” (default in Linux operating
system).
Effect of Bathymetry
Storm surge phenomenon is known to be highly dependent on off shore coastal
bathymetry. Experiments have shown that the surge is very sensitive to basin depths. The
shallowness of the water in coastal regions may considerably modify the surge heights in the
WMO/TCP Training Programme, IIT, Delhi, India
Report of IIT Storm Surge Modeling & Forecasting for Sri Lanka
region. It has been seen that the cyclones of similar intensity land falling at various locations in the
same basin generate surges of varying amplitude.
In order to study the effect of bathymetry on the surge amplitude, experiments will be
carried out with:
(i).
(ii).
(iii).
(iv).
3.2
Experiment 1: uniform depth of entire basin (10m),
Experiment 2: uniform depth of entire basin (50m),
Experiment 3: uniform depth of entire basin (100m),
Experiment 4: shallower region in coastal areas and deeper water elsewhere
(uniform depth of 5m if depth is less than or equal to 40 m).
Effect of Landfall Angle
The location of highest surge depends predominantly on the angle of landfall. It has been
the experience that the cyclones of similar intensity generate surges of different amplitudes
depending upon the angle of landfall at a particular location. Although it may be considered to be
the effect of offshore bathymetry but if experiments performed with uniform depth may provide
important information about the relationships between angle of landfall and the location (distance
from landfall) and amplitude of surges. Surge simulation with idealized cyclones land falling the
coast from different angles in a basin of uniform depth will be carried out.
Following experiments will be done:
(i). Experiment 5: Cyclone landfalling perpendicular to the coast,
(ii). Experiment 6: Cyclone landfalling with southerly track,
(iii). Experiment 7: Cyclone landfalling with more southerly track,
3.3
Sensitivity to wind stress forcing
Wind field associated with cyclone is the foremost requirement for the computation of
surges. In the absence of real-time wind observations the storm surge modeling/prediction
depends upon the computations of the winds is based on certain cyclone characteristics estimated
from satellite imageries in most of the regions and NWP product in certain cases. For computation
of the winds from observed/estimated parameters of the cyclone differing assumptions are made
by various workers about the dependence of surface atmospheric pressure and wind speed on
distance from the center of the cyclone using different wind models. One of the most important
questions raised in this regard is whether or not any of these cyclone models give an accurate
estimate of the associated wind field. Since the computation of storm surges is carried out by
forcing the ocean model by wind stress which is proportional to square of the speed of the wind,
any error in estimation of the wind may lead to substantial error in wind stress and thus in storm
surge.
In most of the cases wind field is computed using cyclone parameters (i) the pressure drop,
(ii) maximum sustained winds, and (iii) the radii of maximum wind. Numerical experiments will be
carried out to examine the sensitivity of these parameters on the surge development.
Experiments will be carried out with
(i)
(ii)
(iii)
Experiment 8-10: DP  5 hPa
Experiment 11-13: DP  10 hPa
Experiment 14-16: Rmax  10 Kms
These experiments will be able to tell that which of the parameters has greater sensitivity and
also about possible the care to be taken in estimating the surge.
3.4
Impact of Duration of Cyclone over the Sea.
Evolution and amplitude of surge depends critically upon the duration of the cyclone over
continental shelf, especially for closed regions like Bay of Bengal.
Fast moving cyclones are for less duration over the continental shelf and therefore energy
transfer from cyclone to sea is less compared to the cyclones which stay for longer period.
WMO/TCP Training Programme, IIT, Delhi, India
Report of IIT Storm Surge Modeling & Forecasting for Sri Lanka
Normally the amplitude of surge generated by fast moving cyclone is less than the slow moving
cyclone.
Following experiments are planned to test the hypothesis:
(i). Experiment 17: Cyclone duration 36 hours
(ii). Experiment 18: Cyclone duration 18 hours
4.
4.1
Model Used
IIT (India) Storm Surge Model
The Storm Surge Model developed by the Indian Institute of Technology (IIT) is used for
this study. The model has been mostly applied to studies over Bay of Bengal area. This is the
Location specific vertically integrated model for Sri Lanka. The simulation was performed on the
domain covering the area 77°E to 84°E and 5° to 12°N. The horizontal resolution for this study is
set at 3 km at a time step of 30 seconds.
A case was selected the Subtropical Storm #4 during 19-29 November, 1978 in the Bay of
Bengal. The maximum wind was 90 knots of that storm.
5.
5.1
Results & Discussions
Experiment 0:
Figure 1 shows the location and the amplitude of the surge generated by 1978 Batticaloa
Cyclone using IIT Model. The maximum surge height simulated by IIT model is 3.55m, which is in
good agreement with reported observations.
Figure 1: Surge generated by Batticola 1978 Cyclone (Simulated using IIT Model)
5.2
Effect of Bathymetry
Experiment 1-3:
Figure 2-4 show the results of the experiment 1-3 performed by IIT Model for Sri Lanka
with uniform basin depth of 10, 50 and 100 meters respectively. The experiment 1 gives the
highest surge (6.7m). In experiment 3 the surge height is 0.9m. It can be seen that the surge
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amplitude is highly dependent on the coastal bathymetry. The shallower the water higher the storm
surge. Figure 5 shows the computed surge for shallow continental shelf and actual bathymetry
elsewhere (uniform depth of 5m if depth is less than or equal to 40 m). Model results confirm the
importance of depth specifications on continental shelf. The maximum surge height of this
experiment is 4.2m.
Figure 2: Experiment with uniform depth of 10m
Figure 3: Experiment with uniform depth of 50 m
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Figure 4: Experiment with uniform depth of 100 m
Figure 5: Experiment with shallower water on the continental shelf and real depth elsewhere
5.3
Effect of Landfall Angle
Experiment 5-8:
Figure 6-8 show the amplitude and the location of peak surges associated with the
cyclones of same intensity but land falling with different angles of incidence at Sri Lanka east
coast.
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A comparison of results clearly shows that location and amplitude of the surge are
sensitive to the angle of incidence of cyclone at a particular place. It is seen that the more
southerly track gives lower surge height compare with other two experiments.
Figure 6: Experiment with cyclone landfalling normal to the coast
Figure 7: Experiment with southerly track
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Figure 8: Experiment with more southerly track
5.4
Sensitivity to wind stress forcing
Most of the storm surge model use parametric wind models for computing winds
associated with cyclones in the absence of reliable cyclone winds produced by NWP models.
Cyclone parameters frequently used for computation of winds are radius of maximum sustained
winds and pressure drop at the centre of the cyclone. Several experiments are performed here to
investigate the sensitivity of storm surge to the errors in these input parameters.
Experiment 8-10:
Figure 9 - 11 show the computed surge for pressure drops of 55, 60 and 65 hPa
respectively for experiments with Sri Lanka model. Experiment with pressure drop of 60 hPa is the
real condition experiment. It may be seen from these experiments that an error of ±5 Km in
estimation of pressure drops may lead to the error of up to 6% in estimating the surge amplitude.
Figure 9: Storm surge with error of (-5 hPa) in estimating the pressure drop
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Figure 10: Storm Surge with real pressure drop
Figure 11: Storm surge with error of (+5 hPa) in estimating the pressure drop
Experiment 11-13:
Figure 12 - 14 show the computed surge for pressure drops of 50, 60 and 70 hPa
respectively for experiments with Sri Lanka model. It may be seen from these experiments that an
error of ±10 Km in estimation of pressure drops may lead to the error of up to 12% in estimating
the surge amplitude.
It may be seen from these experiments higher surge height gives when pressure drop is
high. The over estimations of pressure drop may lead to the higher surge amplitude especially
surge amplitude is lower if pressure drop is under estimated.
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Figure 12: Storm Surge with -10 hPA error in estimating the pressure drop
Figure 13: Storm surge with real pressure drop
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Figure 14: Storm Surge with +10 hPa error in estimating the pressure drop
Experiment 14-16:
Figure 15 to 17 show the computed surge for radius of maximum winds 20, 30 and 40 Km
respectively for Sri Lanka. A radius of maximum wind of 30 kms is the real condition experiment.
It may be seen from these results that an error of ± 10 Km in estimation of radius of
maximum sustained wind may lead to the error of up to 25-30% in estimating the surge amplitude.
Figure 15: Storm Surge with -10 Kms error in estimating radius of Maximum wind
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Figure 16: Storm Surge with real radius of maximum wind
Figure 17: Storm Surge with +10 Kms error in estimating radius of maximum wind
5.5
Impact of Duration of Cyclone over the Sea.
Experiment 17-19:
In order to further test our hypothesis that longer the duration of the wind stress on the
ocean larger the amplitude of surge, experiments were performed with IIT model for two cases.
In the first case cyclone stays 36 hours over the ocean before crossing the coast (Figure 18)
and in the second case it stays only 18 hours before landfall (Figure 19). A comparison of two
figures for Sri Lanka shows clearly smaller amplitude and spatial extent of peak surge in the
second case.
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Figure 18: Storm Surge generated by cyclone of duration 36 hours
Figure 19: Storm Surge generated by cyclone of duration 36 hours
Validation Experiments
In order to validate IIT storm surge model several experiments were performed with past
severe cyclonic storms land falling at Sri Lanka coast. Simulated maximum surge has been
compared with available observations.
December 2000 Cyclone:
The amplitude of surge generated by this Cyclone using IIT Model is given in Figure 20.
The maximum surge height simulated by IIT model is 3.55m, which is normally good agreement
with the available observations.
November 1978 Cyclone:
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The result of November 1978 Cyclone shows in Figure 1, and that was the Experiment 0 in
this study. The maximum surge height simulated by IIT model is 1.1m.
December 1964 Cyclone:
The Figure 21 shows the location and the amplitude of the surge generated by this Cyclone
using IIT Model. The maximum surge height simulated by IIT model is 5.6m, which is in good
agreement with reported observations.
Figure 20: Surge generated by December 2000 Cyclone (Simulated using IIT Model)
Figure 21: Surge generated by December 1964 Cyclone (Simulated using IIT Model)
6.
Conclusions
IIT storm surge model has been extensively used to simulate surge generated by severe
cyclonic storms hitting Sri Lanka coast. Comparison of simulated surge with available observations
was made for the cases of December 2000 Cyclone, November 1978 Batticaloa Cyclone and
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December 1964 Cyclone. These experiments gave a good confidence to run the model for
predicting surges in Sri Lanka coast.
Also using track data of 1978, Batticaloa cyclone, 18 experiments were carried out to test
the model sensitivity to various input parameters (bathymetry, landfall angle, pressure drop, and
the radii of maximum wind and the duration of the cyclone over the sea). Results of the
experiments and their significance were examined in detail.
It may be concluded that there will significant difference in forecasting quality when we
operationalise IIT model. The IIT model will provide useful guidance for the forecasters and it will
be very useful to improve their storm surge forecasting abilities.
With implementation of this system, I am confident that in future if there is tropical cyclone
in vicinity of Sri Lanka coast, it would be possible to run the model and potentially give an
enhanced real time storm surge forecast for Sri Lanka.
The knowledge and the experience gained from this training will be shared with the
colleagues at the Sri Lanka Meteorological Department once I go back.
Acknowledgement:
 I would like to record my heartfelt gratitude to Prof. S. K. Dube, Prof A. D. Rao, and Dr
Indu Jain for their guidance and sharing experiences during my stay at IIT Delhi.
 Sincere thanks to TCP Training Programme of World Meteorological Organization
(WMO), without their financial support my training in the India would not have been
realized.
 I would also like to acknowledge to all the staff of Ocean State Forecasting Division,
Center for Atmospheric Sciences, IIT Delhi for their friendly responds and efforts to
provide all necessary help.
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